1. Field of the Invention
The present invention relates generally to a disk unit, and more particularly, to a disk unit constructed so that a rotating cover can be opened to load or remove a disk-shaped recording medium loaded therein.
2. Description of the Related Art
As one type of conventional disk unit, that which is adapted for use in a CD-ROM device connected to a lap-top personal computer is known. Such an arrangement, in which the CD-ROM device is separate from the personal computer, has the advantage of allowing such computers to be made thinner, lighter and more compact.
This type of CD-ROM device is connected to the lap-top personal computer via a cable and a connector. A compact disk (hereinafter xe2x80x9cdiskxe2x80x9d) on which information is recorded is read by an optical pick-up and sent to the computer.
FIGS. 1A and 1B are schematic diagrams showing side views of a conventional disk unit used in such a CD-ROM device, with a cover thereof in a closed state and an open state, respectively.
As shown in FIG. 1A, the CD-ROM device 1 has a tray 2 on which a disk (not shown in the diagram) is loaded and a cover 3 rotatably supported so as to provide access to the tray 2. The cover 3 is opened when removing a disk from or placing a disk on the tray 2 and is retained in a closed position when the disk is loaded.
Reference numeral 4 is an eject switch, slidably disposed on a lateral surface of the tray 2. The eject switch 4 has a hook-like engaging member 4a that retains a retaining member 5 projecting from a lower surface of the cover 3. The eject switch 4 is impelled in a direction A by a spring member not shown in the diagram and thus held at a position at which it engages the retaining member 5.
Accordingly, the cover 3, when in a closed position, is retained by the hook-like engaging member 4a of the eject switch 4 and protects a disk loaded onto a turntable that is not shown in the drawing but which is provided within the tray 2.
As shown in FIG. 1B, the cover 3 is opened by the force of a torsion spring 6 shown by a dotted line in the drawing. Thus, when the eject switch is slid in a B direction so as to release the hook-like engaging member 4a from the retaining member 5 projecting from a lower surface of the cover 3, the force of the torsion spring swings the cover 3 open.
Accordingly, when the eject switch 4 is slid. open, that is, in the B direction that releases the hook-like engaging member 4a from the retaining member 5 projecting from the lower surface of the cover 3, the force of the torsion spring 6 swings the cover 3 open so as to expose the disk loading portion of the device. An operator then removes the disk placed atop the turntable or, alternatively, places a disk on the turntable and then swings the cover to a closed position, thereby engaging the hook-like engaging member 4a with the retaining member 5 projecting from a lower surface of the cover 3.
In a disk unit having a structure like that described above, removing the disk from the device or, alternatively, loading a disk into the device, necessitates manually sliding the eject switch 4 open in order to open the cover 3.
However, such a disk unit structure has a disadvantage in that an operator engaged in operating the personal computer to which the disk unit is connected would be required to search for the eject switch 4. Conventionally, this means that the operator must look away from the display monitor in order to manipulate the disk unit, thus interrupting the use of the computer and creating an inconvenience.
Additionally, with the conventional disk unit having the structure described above, when the eject switch 4 is moved in the direction that opens the cover 3 when removing or loading a disk, the spring force of the torsion spring 6 forces the cover 3 to at once rotate to a fully open position and thus expose the disk loading portion before the disk has stopped rotating, which is undesirable.
Additionally, conventionally when the cover is opened the motor that rotatably drives the turntable is supplied with a counterelectromotive force so as to stop the turntable. However, with disks rotating at high rotational speeds of 30xc3x97 to 40xc3x97, for example, it is difficult to completely halt the rotation of the disk in the short time it takes for the cover 3 to open. As a result, the disk continues to rotate due to inertia even after the cover 3 is opened, which is undesirable.
As a result, the operator must wait for the rotating disk to come to a complete halt before removing the disk, which is inconvenient.
Accordingly, it is an object of the present invention to provide an improved and useful disk unit in which the above-described disadvantages are eliminated.
The above-described object of the present invention is achieved by a disk unit comprising:
a loading portion that accommodates a recording medium;
a main body unit that contains the loading portion;
a cover rotatably attached to the main body unit and capable of moving between a closed position that covers the loading portion and a plurality of open positions that exposes the loading portion;
a retaining member provided on the main body unit for retaining the cover in the closed position;
means for manually moving the retaining member to a release position at which the cover is released from retention in the closed position;
drive means activated in response to an eject signal; and
a drive transmission mechanism that transmits a drive force of the drive means to the retaining member so as to move the retaining member to the release position.
According to this aspect of the invention, the cover retention can be released and the cover opened in response to a signal from an external source such as, for example, a personal computer, thus facilitating removal and loading of a disk to and from the disk unit.
The above-described object of the present invention is also achieved by the disk unit as described above, wherein the retaining member comprises an engaging portion that is accommodated within an aperture in the means for manually moving the retaining member so as to move freely within the aperture when moving toward the release position in response to the eject signal.
According to this aspect of the invention, the retaining member moves to the release position without involving the manual eject means, so a powered eject operation can be performed while at the same time preventing the manual eject means from contacting nearby components.
The above-described object of the present invention is also achieved by the disk unit as described above, wherein the drive transmission mechanism comprises:
a transmission member that moves the retaining member to the release position; and
a reset mechanism that resets the transmission member to an original position when the means for manually moving the retaining member to the release position is operated.
According to this aspect of the invention, the transmission member can be manually reset to an original position if power is cut at an intermediate stage of the powered eject operation.
The above-described object of the present invention is also achieved by the disk unit as described above, wherein the reset mechanism comprises:
a reset projection provided on the retaining member that moves toward the release position when the means for manually moving the retaining member to the release position is operated;
a reset lever that separates another transmission member from the transmission member when the reset projection moves toward the release position; and
an impelling member that returns the transmission members to original positions when the reset lever separates the transmission members from each other.
According to this aspect of the invention, the drive transmission mechanism can be reset to an original position if power is turned OFF at an intermediate stage of the powered eject operation and the eject operation halted.
The above-described object of the present invention is also achieved by the disk unit as described above, further comprising a drive unit for controlling the drive means in response to an eject signal transmitted from a computer connected to the disk unit via a cable.
According to this aspect of the invention, the cover of the disk unit can be opened automatically in response to an external command.
The above-described object of the present invention is also achieved by the disk unit as described above, wherein the cable transmits control signals for reading information recorded on the recording medium.
According to this aspect of the invention, an eject signal can be transmitted using an ordinary cable, without the need for a separate, dedicated cable to transmit the eject command.
The above-described object of the present invention is also achieved by a disk unit comprising:
a loading portion that accommodates a recording medium;
a main body unit that contains the loading portion;
a cover rotatably attached to the main body unit and capable of moving between a closed position that covers the loading portion and a plurality of open positions that exposes the loading portion;
an impelling member provided between the main body unit and the cover for impelling the cover toward the plurality of open positions;
a retaining member provided on the main body unit for retaining the cover in the closed position; and
stopping means for stopping the cover at an intermediate position between the closed position and a fully open position when the retaining member moves to a release position at which the cover is released from retention in the closed position.
According to this aspect of the invention, the rotation of the disk can be stopped while the cover is held at an intermediate open position, after which the disk can be removed or replaced promptly once the cover is fully opened.
The above-described object of the present invention is also achieved by the disk unit as described above, wherein the stopping means comprises:
a cam surface against which the impelling member presses; and
a stepped portion formed on the cam surface that contacts the impelling member and restricts a movement of the cover toward the fully open position.
According to this aspect of the invention, the stopping means can be formed relatively inexpensively and without the need to increase the number of component parts.
The above-described object of the present invention is also achieved by the disk unit as described above, wherein the impelling member comprises a roller that contacts either the cam surface or the stepped portion and rotatably drives either the cam surface or the stepped portion in response to an opening or a closing of the cover.
According to this aspect of the invention, use of the roller smoothes the opening and closing of the cover.
The above-described object of the present invention is also achieved by the disk unit as described above, further comprising a braking mechanism linked to the opening and closing of the cover, such that the braking mechanism brakes the recording medium when the cover is opened and releases the recording medium when the cover is closed.
According to this aspect of the invention, the length of time required for the rotation of the disk to stop once the cover has been opened can be reduced.